National Science Education Standards,Structure of the Earth System, Grades 5-8
Some changes in the solid earth can be described as the "rock cycle." Old rocks at the earth's surface weather, forming sediments that are buried, them compacted, heated, and often recrystallized into new rock. Eventually, those new rocks may be brought to the surface by the forces that drive plate motions, and the rock cycle continues.
1. What does this standard mean?
The continuous changing of rocks from one kind to another over long periods of time is the rock cycle.
The rock cycle is driven by the movement of Earth's plates.
Rocks are placed into three groups according to how they form: Igneous, Sedimentary, Metamorphic.
Igneous rocks form from hot fluid magma within the earth or lava outside the earth.
Weathering and erosion of rocks by wind, water, etc. creates inorganic sediments.
Plant and animal products and remains make up organic sediments.
Sedimentary rocks form from organic and inorganic sediments which cement together over time.
Metamorphic rocks form when chemical reactions, in the form of heat & pressure, change existing rocks into new rocks.
2. What prior knowledge do students need to understand the standard?
Plate tectonics, how earth's lithospheric plates move due to convection in the mantle.
Earth's crust is made of rocks.
Heat & pressure can change the chemical and physical properties of an object.
Difference between magma and lava.
3. What misconceptions might students have around the topics contained in the standard?
The rock cycle is a pathway that moves in one direction.
Some changes in the solid earth can be described as the "rock cycle." Old rocks at the earth's surface weather, forming sediments that are buried, them compacted, heated, and often recrystallized into new rock. Eventually, those new rocks may be brought to the surface by the forces that drive plate motions, and the rock cycle continues.
1. What does this standard mean?
2. What prior knowledge do students need to understand the standard?
3. What misconceptions might students have around the topics contained in the standard?